GMC Denali Women's Road Bike (20"/50cm Frame) 21-speed women's road bike features a lightweight aluminum 19.5-inch frame Alloy calipers and ally brake levers High-profile alloy Vitesse racing rims Shimano derailleur and Shimano Revo shifts makes it easy to change gears quickly and smoothly High-performance 700c tires are up to the challenge of rigorous street racing